import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param pHead1 ListNode类 
     * @param pHead2 ListNode类 
     * @return ListNode类
     */
    public ListNode Merge (ListNode pHead1, ListNode pHead2) {
        // write code here
        if(pHead1==null||pHead2==null){
            return pHead1!=null?pHead1:pHead2;
        }
            if(pHead1.val<=pHead2.val){
                pHead1.next=Merge(pHead1.next,pHead2);
                return pHead1;
            }else{
                pHead2.next=Merge(pHead2.next,pHead1);
                return pHead2;
            }
        
    }
}